What better place to view a film about the transit of Venus than an 18th-century observatory? A once-in-a-lifetime experience, the opportunity for us to watch the planet traverse the face of the sun in June last year was the last this century and will not recur until 2117.
To mark the occasion, Modern Art Oxford and the University of Oxford commissioned Turner prizewinning artist Simon Starling to film the transit. The 35-millimetre film that Starling shot in Hawaii and Tahiti, Black Drop, is now being shown in the Radcliffe Observatory, Oxford, which was built shortly after the first global scientific effort to record the transit.
Starling’s film is being screened in the elegant Observing Room, which housed optical telescopes to investigate the night skies until the observatory closed in 1934. Conditions are chilly beneath its lofty dome in winter, even with the room’s four full-height triple windows shuttered, but it provides an evocative setting for Starling’s beguiling film, which includes images of 18th and 19th-century transits that occurred during the heyday of the observatory.
Black Drop takes its title from an optical phenomenon that occurs at a critical point during the transit of Venus, when the silhouetted planet is about to touch the sun’s edge – known as its limb – during the ingress and egress of the planet’s transit. At these points the planet appears to distort and elongate. This phenomenon foiled 18th-century observers’ attempts to collect accurate data on the exact time that the planet touched the sun’s limb, which was vital for enabling astronomers to refine their measurement of the mean Earth-sun distance – the astronomical unit. Among many disappointing failures was that of mariner James Cook and his ship’s astronomer Charles Green in 1769, who recorded very different timings for the crucial moments of contact between Venus and the sun’s limb. They did, however, publish their drawings of the black drop phenomenon in 1771.
In 1874, in order to overcome human error in collecting data during transits, the astronomer Pierre Jules César Janssen developed a “revolver photographique”, which he used to take repeated exposures of the 1874 transit of Venus. Unfortunately, the telescope to which Janssen’s chronophotographic device (combining chronometry and photography) was attached was misaligned, leaving half of Venus out of the image. But the revolver photographique had considerable impact on the subsequent development of cinema. This historical link between astronomy and cinema inspired Starling to shoot Black Drop using 35-millimetre film stock, which is being displaced by digital film-making. “Given that no one can predict what technology might be available to record the next transit in 2117, I wanted to ‘bracket’ my film historically between the introduction of Janssen’s revolver and the demise of 35-millimetre film,” he said.
Though much of Starling’s film is comprised of stills, it also includes moving images. Some of these are tracking shots of overlapping historical astronomical drawings and charts pinned onto display panels, but there is also footage of southern-hemisphere observatories and nocturnal skies, and waves washing onto Pacific beaches – signifying the historic importance of Pacific vantage points in observing transits of Venus. Starling evokes extra layers of meaning with footage of the 35-millimetre film being cut and spliced to make the final version. Shots of the editing desks from above show whirring spools of film that resemble miniature solar systems; trembling lengths of 35-millimetre film resemble the wind-blown palm trees of historic vantage points.
Black Drop is an engaging documentary, in which Starling considers astronomers’ historic interest in the transit of Venus, and their endeavours to improve the accuracy of their observations, from the viewpoint of an artist interested in the history of the development of cinema.
The Black Drop film installation runs until 24 March at the Radcliffe Observatory, Oxford, and will be recreated at Modern Art Oxford from 23 August to 8 September. Black Drop has also been published in book form
Read more: www.newscientist.com